U.S. patent application number 15/179395 was filed with the patent office on 2016-12-15 for near field communication antenna, near field communication device and mobile system having the same.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Hyeon-Hee CHOI, Yo-Han JANG, Young-Joo LEE, Young-Ki LEE, Il-jong SONG.
Application Number | 20160365635 15/179395 |
Document ID | / |
Family ID | 57516321 |
Filed Date | 2016-12-15 |
United States Patent
Application |
20160365635 |
Kind Code |
A1 |
JANG; Yo-Han ; et
al. |
December 15, 2016 |
NEAR FIELD COMMUNICATION ANTENNA, NEAR FIELD COMMUNICATION DEVICE
AND MOBILE SYSTEM HAVING THE SAME
Abstract
A near field communication (NFC) antenna includes a first
antenna electrode and a second antenna electrode, and a loop coil.
The first and second antenna electrodes are formed on a first
surface of a substrate. The loop coil is formed on the first
surface of the substrate, is directly coupled between the first
antenna electrode and the second antenna electrode, and includes a
first plurality of turns. The first antenna electrode is located
inside each of the plurality of turns of the loop coil, and the
second antenna electrode is located outside each of the plurality
of turns of the loop coil. An imaginary line passing through the
first antenna electrode and the second antenna electrode is
parallel to one of edges of the substrate. Each of the first
plurality of turns of the loop coil does not overlap each
other.
Inventors: |
JANG; Yo-Han; (Seoul,
KR) ; SONG; Il-jong; (Suwon-si, KR) ; LEE;
Young-Ki; (Incheon, KR) ; LEE; Young-Joo;
(Yongin-si, KR) ; CHOI; Hyeon-Hee; (Hwasung-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD. |
Suwon-si |
|
KR |
|
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
57516321 |
Appl. No.: |
15/179395 |
Filed: |
June 10, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04B 5/0031 20130101;
H04B 5/0081 20130101; H01Q 7/00 20130101; H04B 5/0087 20130101;
H01Q 1/243 20130101; H01Q 1/38 20130101; H04B 5/0056 20130101 |
International
Class: |
H01Q 7/00 20060101
H01Q007/00; H01Q 1/24 20060101 H01Q001/24; H01Q 1/36 20060101
H01Q001/36; H04B 5/00 20060101 H04B005/00; H01Q 1/50 20060101
H01Q001/50 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 12, 2015 |
KR |
10-2015-0083130 |
May 24, 2016 |
KR |
10-2016-0063686 |
Claims
1. A near field communication (NFC) antenna, comprising: a first
antenna electrode and a second antenna electrode, both the first
and the second antenna electrodes being formed on a first surface
of a substrate; and a loop coil formed on the first surface of the
substrate, the loop coil being directly coupled between the first
antenna electrode and the second antenna electrode, and comprising
a first plurality of turns, wherein the first antenna electrode is
located inside each of the first plurality of turns of the loop
coil, and the second antenna electrode is located outside each of
the first plurality of turns of the loop coil, wherein an imaginary
line passing through the first antenna electrode and the second
antenna electrode is parallel to one of edges of the substrate, and
wherein each of the first plurality of turns of the loop coil does
not overlap each other.
2. The NFC antenna of claim 1, wherein the first plurality of turns
of the loop coil pass between the first antenna electrode and the
second antenna electrode.
3. The NFC antenna of claim 1, wherein a distance between the first
antenna electrode and the second antenna electrode is in a range of
2 mm to 20 mm.
4. The NFC antenna of claim 1, wherein each of the first plurality
of turns of the loop coil has a rectangular shape.
5. The NFC antenna of claim 1, wherein each of the first plurality
of turns of the loop coil has a circular shape.
6. The NFC antenna of claim 1, wherein the substrate comprises a
flexible printed circuit board (FPCB).
7. The NFC antenna of claim 1, wherein the substrate is configured
to be installed on a battery of a mobile device, and wherein a
distance between the first antenna electrode and the second antenna
electrode is smaller than 10 mm.
8. The NFC antenna of claim 1, wherein the substrate is configured
to be installed on a back side cover of a mobile device, and
wherein a distance between the first antenna electrode and the
second antenna electrode is smaller than 20 mm.
9. The NFC antenna of claim 1, further comprising: a resonance coil
formed on the first surface of the substrate, the resonance coil
being physically detached from the loop coil, the first antenna
electrode, and the second antenna electrode, and comprising a
second plurality of turns.
10. The NFC antenna of claim 9, wherein the resonance coil is
located inside an innermost turn of the first plurality of turns of
the loop coil.
11. The NFC antenna of claim 10, wherein a distance between the
innermost turn of the first plurality of turns of the loop coil and
an outermost turn of the second plurality of turns of the resonance
coil is less than 2 mm.
12. The NFC antenna of claim 9, wherein a self-resonance frequency
of the resonance coil corresponds to 13.56 MHz.
13. The NFC antenna of claim 9, wherein each of the second
plurality of turns of the resonance coil has a rectangular
shape.
14. The NFC antenna of claim 9, wherein each of the second
plurality of turns of the resonance coil has a circular shape.
15. The NFC antenna of claim 1, further comprising: a resonance
coil formed on the first surface of the substrate, the resonance
coil being physically detached from the loop coil, the first
antenna electrode and the second antenna electrode, and comprising
one turn; and a resonance capacitor coupled between two ends of the
resonance coil.
16. The NFC antenna of claim 15, wherein the resonance coil and the
resonance capacitor are located inside an innermost turn of the
first plurality of turns of the loop coil.
17. The NFC antenna of claim 16, wherein a distance between the
innermost turn of the first plurality of turns of the loop coil and
the resonance coil is less than 2 mm.
18. The NFC antenna of claim 15, wherein a resonance frequency
formed by the resonance coil and the resonance capacitor
corresponds to 13.56 MHz.
19. A near field communication (NFC) device, comprising: an NFC
chip comprising a first transmission electrode and a second
transmission electrode, and configured to generate a transmission
signal and to output the transmission signal through the first
transmission electrode and the second transmission electrode; an
NFC antenna formed on a first surface of a substrate, the NFC
antenna comprising a first antenna electrode, a second antenna
electrode, and a loop coil directly coupled between the first
antenna electrode and the second antenna electrode, and configured
to emit an electromagnetic wave based on the transmission signal;
and a matching circuit coupled to the first transmission electrode,
the second transmission electrode, the first antenna electrode and
the second antenna electrode, and configured to perform impedance
matching between the NFC chip and the NFC antenna, wherein the loop
coil comprises a plurality of turns, the first antenna electrode is
located inside each of the plurality of turns of the loop coil, and
the second antenna electrode is located outside each of the
plurality of turns of the loop coil, wherein an imaginary line
passing through the first antenna electrode and the second antenna
electrode is parallel to one of edges of the substrate, and wherein
each of the plurality of turns of the loop coil does not overlap
each other.
20. A mobile system, comprising: a near field communication (NFC)
device configured to communicate with an external device through
NFC; a memory device configured to store output data; and an
application processor configured to control operations of the NFC
device and the memory device, wherein the NFC device comprises: an
NFC chip comprising a first transmission electrode and a second
transmission electrode, and configured to generate a transmission
signal corresponding to the output data and to output the
transmission signal through the first transmission electrode and
the second transmission electrode; an NFC antenna formed on a first
surface of a substrate, the NFC antenna comprising a first antenna
electrode, a second antenna electrode, and a loop coil directly
coupled between the first antenna electrode and the second antenna
electrode, and configured to emit an electromagnetic wave based on
the transmission signal; and a matching circuit coupled to the
first transmission electrode, the second transmission electrode,
the first antenna electrode, and the second antenna electrode, and
configured to perform impedance matching between the NFC chip and
the NFC antenna, and wherein the loop coil comprises a plurality of
turns, the first antenna electrode is located inside each of the
plurality of turns of the loop coil, and the second antenna
electrode is located outside each of the plurality of turns of the
loop coil, wherein an imaginary line passing through the first
antenna electrode and the second antenna electrode is parallel to
one of edges of the substrate, and wherein each of the plurality of
turns of the loop coil does not overlap each other.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 USC .sctn.119 from
Korean Patent Application No. 10-2015-0083130, filed on Jun. 12,
2015 and Korean Patent Application No. 10-2016-0063686, filed on
May 24, 2016 in the Korean Intellectual Property Office (KIPO), the
contents of which are herein incorporated by reference in their
entireties.
BACKGROUND
[0002] 1. Field
[0003] Methods and apparatuses consistent with exemplary
embodiments relate to a wireless communication technology, and more
particularly to an antenna for near field communication (NFC), an
NFC device including the antenna, and a mobile system including the
NFC device.
[0004] 2. Description of Related Art
[0005] Near field communication (NFC) technology is a short-range
wireless communication technology. As NFC technology has been
developed, NFC devices have been more commonly employed in mobile
devices.
[0006] Mobile NFC devices communicate with each other easily using
NFC. In addition an NFC device can be used for a mobile
payment.
[0007] Generally, an NFC device includes an NFC antenna for
emitting an electromagnetic wave. Production cost and performance
of an NFC device may be dependent on a design of an NFC
antenna.
[0008] Therefore, if production cost of an NFC antenna increases,
production cost of an NFC device and a mobile device including the
NFC antenna may also increase.
SUMMARY
[0009] Exemplary embodiments are directed to an antenna for near
field communication (NFC) that reduces production cost while
maintaining high performance.
[0010] One or more exemplary embodiments are directed to provide an
NFC device including the antenna.
[0011] One or more exemplary embodiments are directed to provide a
mobile system including the NFC device.
[0012] According to an aspect of an exemplary embodiment, there is
provided a near field communication (NFC) antenna, including: a
first antenna electrode and a second antenna electrode formed on a
first surface of a substrate; and a loop coil formed on the first
surface of the substrate, the loop coil being directly coupled
between the first antenna electrode and the second antenna
electrode and including a first plurality of turns, wherein the
first antenna electrode is located inside each of the first
plurality of turns of the loop coil, and the second antenna
electrode is located outside each of first the plurality of turns
of the loop coil.
[0013] The plurality of turns of the loop coil may pass between the
first antenna electrode and the second antenna electrode.
[0014] The plurality of turns of the loop coil may be
non-overlapped with each other.
[0015] Each of the plurality of turns of the loop coil may have a
rectangular shape.
[0016] Each of the plurality of turns of the loop coil may have a
circular shape.
[0017] The substrate may include a flexible printed circuit board
(FPCB).
[0018] The substrate may be configured to be installed on a battery
of a mobile device.
[0019] The substrate may be configured to be installed on a back
side cover of a mobile device.
[0020] The NFC antenna may further include: a resonance coil formed
on the first surface of the substrate, the resonance coil may be
physically detached from the loop coil, the first antenna
electrode, and the second antenna electrode and may include a
second plurality of turns.
[0021] The resonance coil may be located inside an innermost turn
of the first plurality of turns of the loop coil.
[0022] A distance between the innermost turn of the first plurality
of turns of the loop coil and an outermost turn of the second
plurality of turns of the resonance coil may be less than 2mm.
[0023] A self-resonance frequency of the resonance coil may
correspond to 13.56 MHz.
[0024] Each of the second plurality of turns of the resonance coil
may have a rectangular shape.
[0025] Each of the second plurality of turns of the resonance coil
may have a circular shape.
[0026] The NFC antenna may further include: a resonance coil formed
on the first surface of the substrate, the resonance coil being
physically detached from the loop coil, the first antenna electrode
and the second antenna electrode, and including one turn; and a
resonance capacitor coupled between two ends of the resonance
coil.
[0027] The resonance coil and the resonance capacitor may be
located inside an innermost turn of the first plurality of turns of
the loop coil.
[0028] A distance between the innermost turn of the first plurality
of turns of the loop coil and the resonance coil may be less than 2
mm.
[0029] A resonance frequency formed by the resonance coil and the
resonance capacitor may correspond to 13.56 MHz.
[0030] According to an aspect of another exemplary embodiment,
there is provided a near field communication (NFC) device,
including: an NFC chip including a first transmission electrode and
a second transmission electrode, and configured to generate a
transmission signal and to output the transmission signal through
the first transmission electrode and the second transmission
electrode; an NFC antenna formed on a first surface of a substrate,
the NFC antenna including a first antenna electrode, a second
antenna electrode, and a loop coil directly coupled between the
first antenna electrode and the second antenna electrode, and
configured to emit an electromagnetic wave based on the
transmission signal; and a matching circuit coupled to the first
transmission electrode, the second transmission electrode, the
first antenna electrode and the second antenna electrode, and
configured to perform impedance matching between the NFC chip and
the NFC antenna, wherein the loop coil includes a plurality of
turns, the first antenna electrode is located inside each of the
plurality of turns of the loop coil, and the second antenna
electrode is located outside each of the plurality of turns of the
loop coil.
[0031] According to an aspect of yet another exemplary embodiment,
there is provided a mobile system, including: a near field
communication (NFC) device configured to communicate with an
external device through NFC; a memory device configured to store
output data; and an application processor configured to control
operations of the NFC device and the memory device, wherein the NFC
device includes: an NFC chip including a first transmission
electrode and a second transmission electrode, and configured to
generate a transmission signal corresponding to the output data and
to output the transmission signal through the first transmission
electrode and the second transmission electrode; an NFC antenna
formed on a first surface of a substrate, the NFC antenna including
a first antenna electrode, a second antenna electrode, and a loop
coil directly coupled between the first antenna electrode and the
second antenna electrode, and configured to emit an electromagnetic
wave based on the transmission signal; and a matching circuit
coupled to the first transmission electrode, the second
transmission electrode, the first antenna electrode, and the second
antenna electrode, and configured to perform impedance matching
between the NFC chip and the NFC antenna, and wherein the loop coil
includes a plurality of turns, the first antenna electrode is
located inside each of the plurality of turns of the loop coil, and
the second antenna electrode is located outside each of the
plurality of turns of the loop coil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Illustrative, non-limiting exemplary embodiments will be
more clearly understood from the following detailed description in
conjunction with the accompanying drawings.
[0033] FIG. 1 is a diagram illustrating a mobile device according
to one or more exemplary embodiments.
[0034] FIG. 2 is a block diagram illustrating a near field
communication (NFC) device according to one or more exemplary
embodiments.
[0035] FIGS. 3 and 4 are diagrams illustrating examples of an NFC
antenna included in the NFC device of FIG. 2 according to one or
more exemplary embodiments.
[0036] FIG. 5 is a diagram illustrating a substrate on which an
antenna is formed according to one or more exemplary
embodiments.
[0037] FIG. 6 is a block diagram illustrating an example of the NFC
device of FIG. 2.
[0038] FIG. 7 is a block diagram illustrating an example of a
transmit circuit included in the NFC device of FIG. 6.
[0039] FIG. 8 is a block diagram illustrating an example of an NFC
device of FIG. 2.
[0040] FIG. 9 is a block diagram illustrating an example of an NFC
device of FIG. 2.
[0041] FIG. 10 is a diagram illustrating an example of an NFC
antenna included in the NFC device of FIG. 2.
[0042] FIG. 11 is a block diagram illustrating an example of the
NFC device of FIG. 2.
[0043] FIG. 12 is a diagram illustrating an example of an NFC
antenna included in the NFC device of FIG. 2.
[0044] FIG. 13 is a block diagram illustrating an example of the
NFC device of FIG. 2.
[0045] FIGS. 14 and 15 are diagrams illustrating examples of
installation of the NFC device of FIG. 2 in a mobile device
according to one or more exemplary embodiments.
[0046] FIG. 16 is a block diagram illustrating a mobile system
according to an exemplary embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0047] Various exemplary embodiments will be described more fully
with reference to the accompanying drawings, in which one or more
exemplary embodiments are shown. The present inventive concept may,
however, be embodied in many different forms and should not be
construed as limited to the exemplary embodiments set forth herein.
Rather, these exemplary embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the present inventive concept to those skilled in the art.
Like reference numerals refer to like elements throughout this
application.
[0048] It will be understood that, although the terms first,
second, etc. may be used herein to describe various elements, these
elements should not be limited by these terms. These terms are used
to distinguish one element from another. For example, a first
element could be termed a second element, and, similarly, a second
element could be termed a first element, without departing from the
scope of the present inventive concept. As used herein, the term
"and/or" includes any and all combinations of one or more of the
associated listed items.
[0049] It will be understood that when an element is referred to as
being "connected" or "coupled" to another element, it can be
directly connected or coupled to the other element, or intervening
elements may be present. In contrast, when an element is referred
to as being "directly connected" or "directly coupled" to another
element, there are no intervening elements present. Other words
used to describe the relationship between elements should be
interpreted in a like fashion (e.g., "between" versus "directly
between," "adjacent" versus "directly adjacent," etc.).
[0050] The terminology used herein is for the purpose of describing
particular exemplary embodiments and is not intended to be limiting
of the inventive concept. As used herein, the singular forms "a,"
"an" and "the" are intended to include the plural forms as well,
unless the context clearly indicates otherwise. It will be further
understood that the terms "comprises," "comprising," "includes"
and/or "including," when used herein, specify the presence of
stated features, integers, steps, operations, elements, and/or
components, but do not preclude the presence or addition of one or
more other features, integers, steps, operations, elements,
components, and/or groups thereof.
[0051] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
inventive concept belongs. It will be further understood that
terms, such as those defined in commonly used dictionaries, should
be interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0052] FIG. 1 is a diagram illustrating a mobile device according
to one or more exemplary embodiments.
[0053] Referring to FIG. 1, a mobile device 10 includes a near
field communication (NFC) device 20. The NFC device 20 included in
the mobile device 10 communicates with an external NFC device 30
(e.g., an NFC reader or an NFC card) through NFC.
[0054] For example, the NFC device 20 may alternately perform an
operation of detecting whether an NFC card is near the NFC device
20 and an operation of detecting whether an NFC reader is near the
NFC device 20.
[0055] When the NFC device 20 detects an NFC reader near the NFC
device 20, the NFC device 20 may operate in a card mode, in which
the NFC device 20 operates as a card. In the card mode, the NFC
device 20 may communicate data with the NFC reader based on an
electromagnetic wave EMW emitted from the NFC reader.
[0056] When the NFC device 20 detects an NFC card near the NFC
device 20, the NFC device 20 may operate in a reader mode, in which
the NFC device 20 operates as a reader. In the reader mode, the NFC
device 20 may emit an electromagnetic wave EMW to communicate data
with the NFC card.
[0057] In one or more exemplary embodiments, the mobile device 10
may be a mobile device such as a cellular phone, a smart phone, a
tablet computer, a laptop computer, a personal digital assistant
(PDA), a portable multimedia player (PMP), a digital camera, a
music player, a portable game console, a navigation system, etc. In
other exemplary embodiments, the mobile device 10 may be a wearable
electronic device such as a smart watch, a wrist band type
electronic device, a necklace type electronic device, a glasses
type electronic device, etc.
[0058] FIG. 2 is a block diagram illustrating a near field
communication (NFC) device according to one or more exemplary
embodiments.
[0059] An NFC device 20 included in the mobile device 10 of FIG. 1
may be implemented as the NFC device 20 of FIG. 2.
[0060] Referring to FIG. 2, the NFC device 20 may include an NFC
antenna 100, a matching circuit 200, and an NFC chip 300.
[0061] The NFC antenna 100 may include a first antenna electrode
AED1 and a second antenna electrode AED2. The NFC antenna 100 may
be coupled to the matching circuit 200 through the first antenna
electrode AED1 and the second antenna electrode AED2. The NFC
antenna 100 may further include a loop coil, which may be coupled
between the first antenna electrode AED 1 and the second antenna
electrode AED2, and includes a plurality of turns.
[0062] Generally, an NFC antenna according to one or more exemplary
embodiments may be formed on one surface of a substrate. That is,
the first antenna electrode AED1, the second antenna electrode
AED2, and the loop coil included in the NFC antenna 100 may all be
formed on a first surface of the substrate, and two ends of the
loop coil may be directly coupled to the first antenna electrode
AED 1 and the second antenna electrode AED2, respectively, on the
first surface of the substrate.
[0063] The matching circuit 200 may be coupled between the NFC
antenna 100 and the NFC chip 300. The matching circuit 200 may
perform impedance matching between the NFC antenna 100 and the NFC
chip 300. The matching circuit 200 may include a capacitor that
forms a resonance circuit together with the NFC antenna 100. A
resonance frequency of the NFC device 20 may be adjusted to a
desired frequency (e.g., 13.56 MHz) based on a capacitance of the
capacitor included in the matching circuit 200.
[0064] In the reader mode, the NFC chip 300 may generate a
transmission signal and provide the transmission signal to the NFC
antenna 100 through the matching circuit 200. The NFC antenna 100
may emit the electromagnetic wave EMW based on the transmission
signal to communicate data with an external NFC card. Because the
external NFC card includes a resonance circuit that includes an
antenna having an inductor and a resonance capacitor, a mutual
induction may occur between the NFC antenna 100 and the external
NFC card, which is near the NFC device 20, while the NFC antenna
100 emits the electromagnetic wave EMW. Therefore, the external NFC
card may receive the transmission signal by demodulating a signal
generated by the mutual induction.
[0065] In the card mode, because a mutual induction occurs between
the NFC antenna 100 and an external NFC reader by the
electromagnetic wave EMW emitted from the external NFC reader, the
NFC antenna 100 may provide an antenna voltage, which is generated
at the first antenna electrode AED1 and the second antenna
electrode AED2 through the mutual induction, to the NFC chip 300
through the matching circuit 200. The NFC chip 300 may receive data
transmitted from the external NFC reader by demodulating the
antenna voltage.
[0066] FIGS. 3 and 4 are diagrams illustrating examples of an NFC
antenna included in the NFC device of FIG. 2.
[0067] Referring to FIGS. 3 and 4, an NFC antenna 100a may be
formed on a substrate 110.
[0068] The NFC antenna 100a may include the first antenna electrode
AED1, the second antenna electrode AED2, and a loop coil 120 formed
on a first surface (e.g., an upper surface) of the substrate 110.
The first antenna electrode AED1 and the second antenna electrode
AED2 may be spaced apart from each other. In addition, as
illustrated in FIGS. 3 and 4, the first antenna electrode AED1 and
the second antenna electrode AED2 may be formed on the first
surface of the substrate 110 such that an imaginary line IL passing
through the first antenna electrode AED 1 and the second antenna
electrode AED2 is parallel to one of edges of the substrate
110.
[0069] The loop coil 120 may include a plurality of turns. The loop
coil 120 may be directly coupled between the first antenna
electrode AED 1 and the second antenna electrode AED2 on the first
surface of the substrate 110. The plurality of turns of the loop
coil 120 may be non-overlapped with each other. In one or more
exemplary embodiments, the loop coil 120 may be formed of any metal
material having a high conductivity, such as copper, silver,
aluminum, etc.
[0070] In FIG. 3, the loop coil 120 is illustrated to include two
turns. In FIG. 4, the loop coil 120 is illustrated to include five
turns. However, exemplary embodiments are not limited thereto, and
the loop coil 120 may include more than two turns.
[0071] As illustrated in FIGS. 3 and 4, the first antenna electrode
AED1 may be located inside each of the plurality of turns of the
loop coil 120, and the second antenna electrode AED1 may be located
outside each of the plurality of turns of the loop coil 120.
[0072] That is, the plurality of turns of the loop coil 120 may be
formed to pass between the first antenna electrode AED 1 and the
second antenna electrode AED2. Therefore, a first end of the coop
coil 120 may be directly coupled to the first antenna electrode
AED1 inside the plurality of turns of the loop coil 120, and a
second end of the coop coil 120 may be directly coupled to the
second antenna electrode AED2 outside the plurality of turns of the
loop coil 120.
[0073] In FIGS. 3 and 4, each of the plurality of turns of the loop
coil 120 is illustrated to have a rectangular shape. However,
exemplary embodiments are not limited thereto, and each of the
plurality of turns of the loop coil 120 may have a circular shape,
an oval shape, or any other shape.
[0074] In the NFC antenna 100a according to exemplary embodiments,
the plurality of turns of the loop coil 120 may be formed to pass
between the first antenna electrode AED1 and the second antenna
electrode AED2, such that the first antenna electrode AED1 may be
located inside each of the plurality of turns of the loop coil 120
and the second antenna electrode AED1 may be located outside each
of the plurality of turns of the loop coil 120. Therefore, two ends
of the loop coil 120 may be directly coupled, respectively, to the
first antenna electrode AED 1 and the second antenna electrode AED2
on the first surface of the substrate 110 while the plurality of
turns of the loop coil 120 may not overlap with each other.
[0075] As described above, because the NFC antenna 100a according
to one or more exemplary embodiments is formed on one surface of
the substrate 110, production cost of the NFC antenna 100a may
decrease, production yield of the NFC antenna 100a may increase,
and a thickness of the NFC antenna 100a may decrease.
[0076] FIG. 5 is a diagram illustrating a substrate on which an
antenna is formed according to one or more exemplary
embodiments.
[0077] In one or more exemplary embodiments, the substrate 110 may
correspond to a printed circuit board (PCB). In other exemplary
embodiments, the substrate 110 may correspond to a flexible printed
circuit board (FPCB).
[0078] In one or more exemplary embodiments, as illustrated in FIG.
5, the NFC antenna 100a may further include a magnetic sheet 160
disposed under a second surface (e.g., a lower surface) of the
substrate 110. The second surface corresponds to an opposite
surface of the first surface of the substrate 110 on which the
first antenna electrode AED1, the second antenna electrode AED2,
and the loop coil 120 are formed. That is, the magnetic sheet 160
may be disposed in a direction opposite to which the loop coil 120
emits the electromagnetic wave EMW. The magnetic sheet 160 may
improve magnetic field radiation efficiency of the loop coil 120 by
preventing the magnetic field for NFC from being reduced by an eddy
current caused by a change of the magnetic field at the substrate
110. For example, the magnetic sheet 160 may be a ferrite sheet or
a magneto-dielectric material (MDM) sheet.
[0079] FIG. 6 is a block diagram illustrating an example of the NFC
device of FIG. 2.
[0080] Referring to FIG. 6, the NFC device 20a may include an NFC
antenna 100a, a matching circuit 200a, and an NFC chip 300a.
[0081] The NFC antenna 100a included in the NFC device 20a of FIG.
6 may be implemented with the NFC antenna 100a of FIGS. 3 and
4.
[0082] In FIG. 6, the NFC antenna 100a is represented as an
equivalent circuit of the NFC antenna 100a of FIGS. 3 and 4. That
is, the loop coil 120 included in the NFC antenna 100a is
represented as an inductor LL in FIG. 6.
[0083] The matching circuit 200a may be coupled between the NFC
antenna 100a and the NFC chip 300a. For example, the matching
circuit 200a may be coupled to the NFC antenna 100a through the
first antenna electrode AED 1 and the second antenna electrode
AED2, and be coupled to the NFC chip 300a through a first
transmission electrode TX1 and a second transmission electrode TX2.
The matching circuit 200a may perform impedance matching between
the NFC antenna 100a and the NFC chip 300a.
[0084] In one or more exemplary embodiments, the matching circuit
200a may include a first capacitor C1, a second capacitor C2, and a
third capacitor C3. The first capacitor C1 may be coupled between
the first antenna electrode AED1 and the second antenna electrode
AED2. The first capacitor C1 may form a resonance circuit together
with the loop coil 120 included in the NFC antenna 100a. A
resonance frequency of the NFC device 20a may be adjusted to a
desired frequency (e.g., 13.56 MHz) by controlling a capacitance of
the first capacitor C1. The second capacitor C2 may be coupled
between the first antenna electrode AED1 and the first transmission
electrode TX1. The third capacitor C3 may be coupled between the
second antenna electrode AED2 and the second transmission electrode
TX2. However, matching circuit 200a of FIG. 6 is only an example.
According to one or more exemplary embodiments, the matching
circuit 200a may be implemented in various structures to perform
impedance matching between the NFC antenna 100a and the NFC chip
300a.
[0085] The NFC chip 300a may include a central processing unit
(CPU) 310, a memory device 320, a first modulator 331, an
oscillator 333, a mixer 335, and a transmit circuit 330.
[0086] When the NFC chip 300a performs a transmit operation in the
reader mode, the CPU 310 may read out output data TD from the
memory device 320 to provide the output data TD to the first
modulator 331, the first modulator 331 may modulate the output data
TD to generate a modulation signal MS, the oscillator 333 may
generate a carrier signal CW having a carrier frequency (e.g.,
13.56 MHz), and the mixer 335 may generate a transmission
modulation signal TMS by synthesizing the carrier signal CW with
the modulation signal MS.
[0087] The transmit circuit 330 may be coupled between a supply
voltage VDD and a ground voltage GND.
[0088] The transmit circuit 330 may output the transmission signal
TS, which corresponds to the transmission modulation signal TMS
received from the mixer 335, through the first transmission
electrode TX1 and the second transmission electrode TX2. The NFC
antenna 100a may emit the electromagnetic wave EMW based on the
transmission signal TS.
[0089] In one or more exemplary embodiments, the transmit circuit
330 may output the transmission signal TS corresponding to the
transmission modulation signal TMS through the first transmission
electrode TX1 and the second transmission electrode TX2 by
connecting the first transmission electrode TX1 and the second
transmission electrode TX2 to the supply voltage VDD through a
pull-up load, or to the ground voltage GND through a pull-down load
based on the transmission modulation signal TMS.
[0090] For example, the transmit circuit 330 may connect the first
transmission electrode TX1 to the supply voltage VDD through the
pull-up load and connect the second transmission electrode TX2 to
the ground voltage GND through the pull-down load, or connect the
first transmission electrode TX1 to the ground voltage GND through
the pull-down load and connect the second transmission electrode
TX2 to the supply voltage VDD through the pull-up load based on the
transmission modulation signal TMS to output the transmission
signal TS corresponding to the transmission modulation signal TMS
through the first transmission electrode TX1 and the second
transmission electrode TX2.
[0091] When the transmit circuit 330 connects the first
transmission electrode TX1 to the supply voltage VDD through the
pull-up load and connects the second transmission electrode TX2 to
the ground voltage GND through the pull-down load, an output
current may be generated from the supply voltage VDD, be provided
to the matching circuit 200a and the NFC antenna 100a through the
first transmission electrode TX1, and be sunk to the ground voltage
GND through the second transmission electrode TX2.
[0092] When the transmit circuit 330 connects the first
transmission electrode TX1 to the ground voltage GND through the
pull-down load and connects the second transmission electrode TX2
to the supply voltage VDD through the pull-up load, the output
current may be generated from the supply voltage VDD, be provided
to the matching circuit 200a and the NFC antenna 100a through the
second transmission electrode TX2, and be sunk to the ground
voltage GND through the first transmission electrode TX1.
[0093] FIG. 7 is a block diagram illustrating an example of a
transmit circuit included in the NFC device of FIG. 6.
[0094] Referring to FIG. 7, the transmit circuit 330 may include a
first pull-up transistor MP0, a second pull-up transistor MP1, a
first pull-down transistor MN0, a second pull-down transistor MN1,
and a driving circuit 337.
[0095] The first pull-up transistor MP0 and the second pull-up
transistor MP1 may be p-type metal oxide semiconductor (PMOS)
transistors. The first pull-down transistor MN0 and the second
pull-down transistor MN1 may be n-type metal oxide semiconductor
(NMOS) transistors.
[0096] The first pull-up transistor MP0 may be coupled between the
supply voltage VDD and the first transmission electrode TX1, and
the first pull-down transistor MN0 may be coupled between the first
transmission electrode TX1 and the ground voltage GND.
[0097] The second pull-up transistor MP1 may be coupled between the
supply voltage VDD and the second transmission electrode TX2, and
the second pull-down transistor MN1 may be coupled between the
second transmission electrode TX2 and the ground voltage GND.
[0098] The driving circuit 337 may drive the first pull-up
transistor MP0 using a first pull-up driving signal UDS0, drive the
first pull-down transistor MN0 using a first pull-down driving
signal DDS0, drive the second pull-up transistor MP1 using a second
pull-up driving signal UDS1, and drive the second pull-down
transistor MN1 using a second pull-down driving signal DDS1.
[0099] The driving circuit 337 may turn on one of the first pull-up
transistor MP0 and the first pull-down transistor MN0, and turn on
one of the second pull-up transistor MP1 and the second pull-down
transistor MN1 based on the transmission modulation signal TMS
received from the mixer 335.
[0100] For example, the driving circuit 337 may turn on the first
pull-up transistor MP0 and the second pull-down transistor MN1, and
turn off the second pull-up transistor MP1 and the first pull-down
transistor MN0, or turn on the second pull-up transistor MP1 and
the first pull-down transistor MN0, and turn off the first pull-up
transistor MP0 and the second pull-down transistor MN1 based on the
transmission modulation signal TMS to output the transmission
signal TS, which corresponds to the transmission modulation signal
TMS, through the first transmission electrode TX1 and the second
transmission electrode TX2.
[0101] FIG. 8 is a block diagram illustrating an example of an NFC
device of FIG. 2.
[0102] Referring to FIG. 8, an NFC device 20b may include an NFC
antenna 100a, a matching circuit 200b, and an NFC chip 300b.
[0103] The NFC antenna 100a included in the NFC device 20b of FIG.
8 may be the same as the NFC antenna 100a included in the NFC
device 20a of FIG. 6.
[0104] The matching circuit 200b may be coupled between the NFC
antenna 100a and the NFC chip 300b. For example, the matching
circuit 200b may be coupled to the NFC antenna 100a through the
first antenna electrode AED 1 and the second antenna electrode
AED2, and be coupled to the NFC chip 300b through the first
transmission electrode TX1, the second transmission electrode TX2,
and a reception electrode RX. The matching circuit 200b may perform
impedance matching between the NFC antenna 100a and the NFC chip
300b.
[0105] Compared with the matching circuit 200a included in the NFC
device 20a of FIG. 6, the matching circuit 200b included in the NFC
device 20b of FIG. 8 may further include a fourth capacitor C4. The
fourth capacitor C4 may be coupled between the first antenna
electrode AED1 and the reception electrode RX. According to one or
more exemplary embodiments, the fourth capacitor C4 may be coupled
between the second antenna electrode AED2 and the reception
electrode RX. However, the matching circuit 200b illustrated in
FIG. 8 is only an example. According to one or more exemplary
embodiments, the matching circuit 200b may be implemented in
various structures to perform impedance matching between the NFC
antenna 100a and the NFC chip 300b.
[0106] Compared with the NFC chip 300a included in the NFC device
20a of FIG. 6, the NFC chip 300b included in the NFC device 20b of
FIG. 8 may further include a first demodulator 340.
[0107] As described above, in the reader mode, the NFC antenna 100a
may emit the electromagnetic wave EMW to communicate data with an
external NFC card. Because the external NFC card includes a
resonance circuit that includes an antenna having an inductance
component and a resonance capacitor, a mutual induction may occur
between the NFC antenna 100a and the external NFC card, which is
near the NFC device 20b, while the NFC antenna 100a emits the
electromagnetic wave EMW. Therefore, an antenna voltage may be
generated at the first antenna electrode AED1 and the second
antenna electrode AED2 through the mutual induction.
[0108] The antenna voltage may be provided to the NFC chip 300b
through the fourth capacitor C4 and the reception electrode RX as a
reception signal.
[0109] When the NFC chip 300b performs a receive operation in the
reader mode, the first demodulator 340 may generate input data by
demodulating the reception signal received through the reception
electrode RX, and provide the input data to the CPU 310. The CPU
310 may store the input data in the memory device 320.
[0110] FIG. 9 is a block diagram illustrating an example of an NFC
device of FIG. 2.
[0111] Referring to FIG. 9, the NFC device 20c may include an NFC
antenna 100a, a matching circuit 200c, and an NFC chip 300c.
[0112] The NFC antenna 100a included in the NFC device 20c of FIG.
9 may be the same as the NFC antenna 100a included in the NFC
device 20a of FIG. 6.
[0113] The matching circuit 200c may be coupled between the NFC
antenna 100a and the NFC chip 300c. For example, the matching
circuit 200c may be coupled to the NFC antenna 100a through the
first antenna electrode AED 1 and the second antenna electrode
AED2, and be coupled to the NFC chip 300c through the first
transmission electrode TX1, the second transmission electrode TX2,
a reception electrode RX, a first power electrode L1, and a second
power electrode L2. The matching circuit 200c may perform impedance
matching between the NFC antenna 100a and the NFC chip 300c.
[0114] Compared with the matching circuit 200b included in the NFC
device 20b of FIG. 8, the matching circuit 200c included in the NFC
device 20c of FIG. 9 may further include a fifth capacitor C5 and a
sixth capacitor C6. The fifth capacitor C5 may be coupled between
the first antenna electrode AED1 and the first power electrode L1.
The sixth capacitor C6 may be coupled between the second antenna
electrode AED2 and the second power electrode L2. However, matching
circuit 200c illustrated in FIG. 9 is only an example. According to
one or more exemplary embodiments, the matching circuit 200c may be
implemented in various structures to perform impedance matching
between the NFC antenna 100a and the NFC chip 300c.
[0115] Compared with the NFC chip 300b included in the NFC device
20b of FIG. 8, the NFC chip 300c included in the NFC device 20c of
FIG. 9 may further include a rectifier 351, a regulator 353, a
power switch 357, a second demodulator 360, and a second modulator
370.
[0116] As described above, in the card mode, the NFC device 20c may
communicate with an external NFC reader using the electromagnetic
wave EMW emitted by the external NFC reader. That is, a mutual
induction may occur between the NFC antenna 100a and the external
NFC reader based on the electromagnetic wave EMW emitted by the
external NFC reader. Therefore, an antenna voltage VAN may be
generated at the first antenna electrode AED1 and the second
antenna electrode AED2 through the mutual induction.
[0117] The antenna voltage VAN may be transferred to the first
power electrode L1 and the second power electrode L2 through the
fifth capacitor C5 and the sixth capacitor C6, respectively.
[0118] The rectifier 351 may generate a first voltage V1, which is
a direct voltage, by rectifying the antenna voltage VAN received
through the first power electrode L1 and the second power electrode
L2.
[0119] The regulator 353 may generate an internal voltage VINT,
which has a voltage level of a predetermined magnitude usable in
the NFC chip 300c, using the first voltage V1.
[0120] The CPU 310 may control the overall operation of the NFC
chip 300c. The CPU 310 may operate using the supply voltage VDD
provided by a power source, such as a battery. In addition, the CPU
310 may receive the internal voltage VINT from the regulator 353
through the power switch 357. When the supply voltage VDD is equal
to or higher than a predetermined voltage level, the CPU 310 may
operate using the supply voltage VDD and disable a switch control
signal SCS to turn off the power switch 357. When the supply
voltage VDD is lower than the predetermined voltage level, the CPU
310 may enable the switch control signal SCS to turn on the power
switch 357 such that the CPU 310 may operate using the internal
voltage VINT provided by the regulator 353.
[0121] When the NFC chip 300c performs the receive operation in the
card mode, the second demodulator 360 may generate input data by
demodulating a signal received through the first power electrode L1
and the second power electrode L2, and provide the input data to
the CPU 310. The CPU 310 may store the input data in the memory
device 320.
[0122] When the NFC chip 300c performs the transmit operation in
the card mode, the CPU 310 may read out output data from the memory
device 320 to provide the output data to the second modulator 370,
and the second modulator 370 may modulate the output data to output
a modulation signal through the first power electrode L1 and the
second power electrode L2. For instance, the second modulator 370
may generate the modulation signal by performing a load modulation
on the output data. The NFC antenna 100a may transmit the output
data to the external NFC reader by causing the mutual induction
with the external NFC reader based on the modulation signal.
[0123] FIG. 10 is a diagram illustrating an example of an NFC
antenna included in the NFC device of FIG. 2.
[0124] Referring to FIG. 10, an NFC antenna 100b may be formed on a
substrate 110.
[0125] The NFC antenna 100b may include the first antenna electrode
AED1, the second antenna electrode AED2, a loop coil 120, and a
resonance coil 130 formed on a first surface (e.g., an upper
surface) of the substrate 110.
[0126] The first antenna electrode AED1, the second antenna
electrode AED2, and the loop coil 120 included in the NFC antenna
100b of FIG. 10 may be the same as the first antenna electrode
AED1, the second antenna electrode AED2, and the loop coil 120
included in the NFC antenna 100a of FIGS. 3 and 4. Therefore, the
NFC antenna 100b of FIG. 10 may be the same as the NFC antenna 100a
of FIGS. 3 and 4, except that the NFC antenna 100b further includes
the resonance coil 130.
[0127] Although the loop coil 120 included in the NFC antenna 100b
is illustrated to have two turns in FIG. 10, exemplary embodiments
are not limited thereto as described above with reference to FIGS.
3 and 4. According to one or more exemplary embodiments, the loop
coil 120 may include more than two turns.
[0128] The resonance coil 130 may include a plurality of turns. In
addition, the resonance coil 130 may be formed to be physically
detached from the loop coil 120, the first antenna electrode AED1,
and the second antenna electrode AED2. In one or more exemplary
embodiments, the resonance coil 130 may be formed of any metal
material having a high conductivity, such as copper, silver,
aluminum, etc.
[0129] In one or more exemplary embodiments, the resonance coil 130
may be located inside the loop coil 120. For example, as
illustrated in FIG. 10, the resonance coil 130 may be located
inside an innermost turn of the plurality of turns of the loop coil
120.
[0130] Because a parasitic capacitor is formed between each of the
plurality of turns of the resonance coil 130, the resonance coil
130 may be represented as an equivalent circuit including an
inductor and a capacitor coupled to the inductor in parallel.
Therefore, the resonance coil 130 may be formed to include
appropriate turns such that a self-resonance frequency of the
resonance coil 130 may correspond to 13.56 MHz.
[0131] Because the resonance coil 130 is physically detached from
the loop coil 120, the resonance coil 130 may not receive an
electrical signal from the loop coil 120. However, the resonance
coil 130 may be magnetically coupled with the loop coil 120.
Therefore, the resonance coil 130 may emit an electromagnetic wave
based on the electromagnetic wave EMW received from the loop coil
120.
[0132] In one or more exemplary embodiments, a resonance frequency
of the resonance coil 130 may be substantially the same as the
resonance frequency of the loop coil 120 such that the resonance
coil 130 may receive power efficiently from the electromagnetic
wave EMW emitted by the loop coil 120. For example, the resonance
frequency of the resonance coil 130 and the resonance frequency of
the loop coil 120 may correspond to 13.56 MHz.
[0133] In addition, the resonance coil 130 may be located adjacent
to the loop coil 120 such that the resonance coil 130 may receive
power efficiently from the electromagnetic wave EMW emitted by the
loop coil 120. For example, a distance LLD1 between the innermost
turn of the plurality of turns of the loop coil 120 and an
outermost turn of the plurality of turns of the resonance coil 130
may be less than 2 mm.
[0134] In FIG. 10, each of the plurality of turns of the resonance
coil 130 is illustrated to have a rectangular shape. However,
exemplary embodiments are not limited thereto, and each of the
plurality of turns of the resonance coil 130 may have a circular
shape, an oval shape, or any other shape.
[0135] As described above with reference to FIGS. 3, 4, and 10,
because the NFC antenna 100b is formed on one surface of the
substrate 110, production cost of the NFC antenna 100b may
decrease, production yield of the NFC antenna 100b may increase,
and a thickness of the NFC antenna 100b may decrease.
[0136] In addition, the NFC antenna 100b according to one or more
exemplary embodiments may emit the electromagnetic wave EMW through
the loop coil 120 and additionally emit the electromagnetic wave
EMW through the resonance coil 130, which is magnetically coupled
with the loop coil 120. Because the resonance coil 130 is
physically detached from the matching circuit 200, the resonance
coil 130 may have a relatively high Q factor (quality factor).
Therefore, an intensity of the electromagnetic wave EMW emitted by
the resonance coil 130 may be relatively high. As such, when the
NFC device 20 of FIG. 2 is implemented to include the NFC antenna
100b of FIG. 10, a communication range of the NFC device 20 may be
effectively increased.
[0137] FIG. 11 is a block diagram illustrating an example of the
NFC device of FIG. 2.
[0138] Referring to FIG. 11, an NFC device 20d may include an NFC
antenna 100b, a matching circuit 200, and an NFC chip 300.
[0139] The NFC antenna 100b included in the NFC device 20d of FIG.
11 may be implemented with the NFC antenna 100b of FIG. 10.
[0140] In FIG. 11, the NFC antenna 100b may be represented as an
equivalent circuit of the NFC antenna 100b of FIG. 10. That is, the
loop coil 120 included in the NFC antenna 100b may be represented
as an inductor LL in FIG. 11, and the resonance coil 130 included
in the NFC antenna 100b may be represented as an inductor LR1 and a
capacitor CP coupled to the inductor LR1 in parallel in FIG.
11.
[0141] The matching circuit 200 and the NFC chip 300 included in
the NFC device 20d of FIG. 11 may be implemented with the matching
circuit 200a and the NFC chip 300a included in the NFC device 20a
of FIG. 6, the matching circuit 200b and the NFC chip 300b included
in the NFC device 20b of FIG. 8, or the matching circuit 200c and
the NFC chip 300c included in the NFC device 20c of FIG. 9.
[0142] As described above with reference to FIGS. 10 and 11, the
NFC antenna 100b included in the NFC device 20d may emit the
electromagnetic wave EMW through the loop coil 120 and additionally
emit the electromagnetic wave EMW through the resonance coil 130,
which is magnetically coupled with the loop coil 120. Because the
resonance coil 130 is physically detached from the matching circuit
200, the resonance coil 130 may have a relatively high Q factor
(quality factor). Therefore, an intensity of the electromagnetic
wave EMW emitted by the resonance coil 130 may be relatively high.
As such, a communication range of the NFC device 20d may be
effectively increased.
[0143] FIG. 12 is a diagram illustrating an example of an NFC
antenna included in the NFC device of FIG. 2.
[0144] Referring to FIG. 12, an NFC antenna 100c may be formed on a
substrate 110.
[0145] The NFC antenna 100c may include the first antenna electrode
AED1, the second antenna electrode AED2, a loop coil 120, and a
resonance coil 140, and a resonance capacitor 150 formed on a first
surface (e.g., an upper surface) of the substrate 110.
[0146] The first antenna electrode AED1, the second antenna
electrode AED2, and the loop coil 120 included in the NFC antenna
100c of FIG. 12 may be the same as the first antenna electrode
AED1, the second antenna electrode AED2, and the loop coil 120
included in the NFC antenna 100a of FIGS. 3 and 4. Therefore, the
NFC antenna 100c of FIG. 12 may be the same as the NFC antenna 100a
of FIGS. 3 and 4 except that the NFC antenna 100c further includes
the resonance coil 140 and the resonance capacitor 150.
[0147] Although the loop coil 120 included in the NFC antenna 100c
is illustrated to have two turns in FIG. 12, exemplary embodiments
are not limited thereto as described above with reference to FIGS.
3 and 4. According to one or more exemplary embodiments, the loop
coil 120 may include more than two turns.
[0148] The resonance coil 140 may include one turn. In addition,
the resonance coil 140 may be formed to be physically detached from
the loop coil 120, the first antenna electrode AED1, and the second
antenna electrode AED2. In some exemplary embodiments, the
resonance coil 140 may be formed of any metal material having a
high conductivity, such as copper, silver, aluminum, etc.
[0149] The resonance capacitor 150 may be coupled between two ends
of the resonance coil 140.
[0150] In one or more exemplary embodiments, the resonance coil 140
and the resonance capacitor 150 may be located inside the loop coil
120. For example, as illustrated in FIG. 12, the resonance coil 140
and the resonance capacitor 150 may be located inside an innermost
turn of the plurality of turns of the loop coil 120.
[0151] Because the resonance coil 140 and the resonance capacitor
150 are coupled together in parallel, the resonance coil 140 and
the resonance capacitor 150 may form a resonance circuit. A
capacitance of the resonance capacitor 150 may be adjusted such
that a resonance frequency of the resonance circuit may correspond
to 13.56 MHz.
[0152] Because the resonance coil 140 is physically detached from
the loop coil 120, the resonance coil 140 may not receive an
electrical signal from the loop coil 120. However, the resonance
circuit, which is formed by the resonance coil 140 and the
resonance capacitor 150, may be magnetically coupled with the loop
coil 120. Therefore, the resonance coil 140 may emit an
electromagnetic wave based on the electromagnetic wave EMW received
from the loop coil 120.
[0153] In one or more exemplary embodiments, a resonance frequency
of the resonance circuit may be substantially the same as the
resonance frequency of the loop coil 120 such that the resonance
coil 140 may receive power efficiently from the electromagnetic
wave EMW emitted by the loop coil 120. For example, the resonance
frequency of the resonance circuit and the resonance frequency of
the loop coil 120 may correspond to 13.56 MHz.
[0154] In addition, the resonance coil 140 may be located adjacent
to the loop coil 120 such that the resonance coil 140 may receive
power efficiently from the electromagnetic wave EMW emitted by the
loop coil 120. For example, a distance LLD2 between the innermost
turn of the plurality of turns of the loop coil 120 and the
resonance coil 140 may be less than 2mm.
[0155] In FIG. 12, each of the plurality of turns of the resonance
coil 140 is illustrated to have a rectangular shape. However,
exemplary embodiments are not limited thereto, and each of the
plurality of turns of the resonance coil 140 may have a circular
shape, an oval shape, or any other shape.
[0156] As described above with reference to FIGS. 3, 4, and 12,
because the NFC antenna 100c according to one or more exemplary
embodiments is formed on one surface of the substrate 110,
production cost of the NFC antenna 100c may decrease, production
yield of the NFC antenna 100c may increase, and a thickness of the
NFC antenna 100c may decrease.
[0157] In addition, the NFC antenna 100c according to one or more
exemplary embodiments may emit the electromagnetic wave EMW through
the loop coil 120 and additionally emit the electromagnetic wave
EMW through the resonance coil 140, which is magnetically coupled
with the loop coil 120. Because the resonance coil 140 is
physically detached from the matching circuit 200, the resonance
coil 140 may have a relatively high Q factor (quality factor).
Therefore, an intensity of the electromagnetic wave EMW emitted by
the resonance coil 140 may be relatively high. As such, when the
NFC device 20 of FIG. 2 is implemented to include the NFC antenna
100c of FIG. 12, a communication range of the NFC device 20 may be
effectively increased.
[0158] In addition, while the resonance coil 130 included in the
NFC antenna 100b includes a number of turns such that the
self-resonance frequency of the resonance coil 130 may correspond
to 13.56 MHz, the resonance coil 140 included in the NFC antenna
100c may include one turn, and the resonance frequency of the
resonance circuit formed by the resonance coil 140 and the
resonance capacitor 150 may be set to 13.56 MHz by adjusting the
capacitance of the resonance capacitor 150.
[0159] FIG. 13 is a block diagram illustrating an example of the
NFC device of FIG. 2.
[0160] Referring to FIG. 13, the NFC device 20e may include an NFC
antenna 100c, a matching circuit 200, and an NFC chip 300.
[0161] The NFC antenna 100c included in the NFC device 20e of FIG.
13 may be implemented with the NFC antenna 100c of FIG. 12.
[0162] In FIG. 13, the NFC antenna 100c may be represented as an
equivalent circuit of the NFC antenna 100c of FIG. 12. That is, the
loop coil 120 included in the NFC antenna 100c may be represented
as an inductor LL in FIG. 13, the resonance coil 140 included in
the NFC antenna 100c may be represented as an inductor LR2 in FIG.
13, and the resonance capacitor 150 included in the NFC antenna
100c may be represented as a capacitor CC in FIG. 13.
[0163] The matching circuit 200 and the NFC chip 300 included in
the NFC device 20e of FIG. 13 may be implemented with the matching
circuit 200a and the NFC chip 300a included in the NFC device 20a
of FIG. 6, the matching circuit 200b and the NFC chip 300b included
in the NFC device 20b of FIG. 8, or the matching circuit 200c and
the NFC chip 300c included in the NFC device 20c of FIG. 9.
[0164] As described above with reference to FIGS. 12 and 13, the
NFC antenna 100c included in the NFC device 20e may emit the
electromagnetic wave EMW through the loop coil 120 and additionally
emit the electromagnetic wave EMW through the resonance coil 140,
which is magnetically coupled with the loop coil 120. Because the
resonance coil 140 is physically detached from the matching circuit
200, the resonance coil 140 may have a relatively high Q factor
(quality factor). Therefore, an intensity of the electromagnetic
wave EMW emitted by the resonance coil 140 may be relatively high.
As such, a communication range of the NFC device 20e may be
effectively increased.
[0165] FIGS. 14 and 15 are diagrams illustrating examples of
installation of an NFC antenna included in the NFC device of FIG. 2
in a mobile device.
[0166] In FIG. 14, a back side of the mobile device 10 without a
back side cover is illustrated.
[0167] In one or more exemplary embodiments, as illustrated in FIG.
14, the NFC antenna 100 may be installed on a battery 11 of the
mobile device 10.
[0168] The matching circuit 200 and the NFC chip 300 included in
the NFC device 20 may be disposed inside a main body of the mobile
device 10.
[0169] The first antenna electrode AED1 and the second antenna
electrode AED2 of the NFC antenna 100 may be electrically connected
to the matching circuit 200 through electrodes with which the
battery 11 is coupled to the main body of the mobile device 10.
[0170] The first antenna electrode AED1 and the second antenna
electrode AED2 of the NFC antenna 100 may be disposed close to each
other. For example, as illustrated in FIG. 14, when the substrate
110 including the NFC antenna 100 is installed on the battery 11 of
the mobile device 10, a distance between the first antenna
electrode AED1 and the second antenna electrode AED2 may be in a
range of 2 mm to 10 mm.
[0171] In FIG. 15, a back side cover 13 of the mobile device 10 and
a back side of the mobile device 10 without the back side cover 13
are illustrated.
[0172] In one or more exemplary embodiments, as illustrated in FIG.
15, the NFC antenna 100 may be installed on an inner surface of the
back side cover 13 of the mobile device 10.
[0173] The matching circuit 200 and the NFC chip 300 included in
the NFC device 20 may be disposed inside a main body of the mobile
device 10. In addition, as illustrated in FIG. 15, a first
electrode 15 and a second electrode 17, which are coupled to the
matching circuit 200, may be formed on the back side of the mobile
device 10.
[0174] The first antenna electrode AED1 and the second antenna
electrode AED2 of the NFC antenna 100 may be disposed close to each
other. For example, as illustrated in FIG. 15, when the substrate
110 including the NFC antenna 100 is installed on the inner surface
of the back side cover 13 of the mobile device 10, a distance
between the first antenna electrode AED 1 and the second antenna
electrode AED2 may be in a range of 2 mm to 20 mm.
[0175] When the back side cover 13 is attached to the back side of
the mobile device 10, the first antenna electrode AED1 and the
second antenna electrode AED2 of the NFC antenna 100 may be
electrically connected to the first electrode 15 and the second
electrode 17, respectively. Therefore, the first antenna electrode
AED1 and the second antenna electrode AED2 of the NFC antenna 100
may be electrically connected to the matching circuit 200 through
the first electrode 15 and the second electrode 17,
respectively.
[0176] In one or more exemplary embodiments, the NFC antenna 100
may be installed on an inner surface of a body frame of the mobile
device 10. In this case, a distance between the first antenna
electrode AED 1 and the second antenna electrode AED2 may be in a
range of 1 mm to 20 mm.
[0177] FIG. 16 is a block diagram illustrating a mobile system
according to an exemplary embodiment.
[0178] Referring to FIG. 16, a mobile system 1000 includes an
application processor AP 1100, an NFC device 1200, a memory device
1300, a user interface 1400, and a power supply 1500. The
application processor 1100, the NFC device 1200, the memory device
1300, the user interface 1400, and the power supply 1500 may be
coupled together via an internal bus 1001.
[0179] In one or more exemplary embodiments, the mobile system 1000
may be, for example, a mobile phone, a smart phone, a personal
digital assistant (PDA), a portable multimedia player (PMP), a
digital camera, a camcorder, a music player, a portable game
console, a navigation system, etc.
[0180] The application processor 1100 controls overall operations
of the mobile system 1000. The application processor 1100 may
execute applications, such as a web browser, a game application, a
video player, etc. In one or more exemplary embodiments, the
application processor 1100 may include a single core or multiple
cores. For example, the application processor 1100 may be a
multi-core processor, such as a dual-core processor, a quad-core
processor, a hexa-core processor, etc. The application processor
1100 may include an internal or external cache memory.
[0181] The memory device 1300 stores various data. For example, the
memory device 1300 may store output data to be transmitted to an
external device and input data received from the external device.
In one or more exemplary embodiments, the memory device 1300 may be
an electrically erasable programmable read-only memory (EEPROM), a
flash memory, a phase change random access memory (PRAM), a
resistance random access memory (RRAM), a nano floating gate memory
(NFGM), a polymer random access memory (PoRAM), a magnetic random
access memory (MRAM), a ferroelectric random access memory (FRAM),
etc.
[0182] The NFC device 1200 transmits the output data stored in the
memory device 1300 to the external device through NFC. The NFC
device 1200 receives the input data from the external device
through NFC and stores the input data in the memory device
1300.
[0183] The NFC device 1200 includes an NFC antenna 1210, a matching
circuit 1220, and an NFC chip 1230.
[0184] The NFC device 1200 may be implemented with the NFC device
20 of FIG. 2.
[0185] The user interface 1400 may include at least one input
device, such as a keypad, a touch screen, etc., and at least one
output device, such as a speaker, a display device, etc. The power
supply 1500 may supply a power supply voltage to the mobile system
1000.
[0186] In one or more exemplary embodiments, the mobile system 1000
may further include an image processor, and/or a storage device,
such as a memory card, a solid state drive (SSD), etc.
[0187] In one or more exemplary embodiments, the mobile system 1000
and/or components of the mobile system 1000 may be packaged in
various forms, such as package on package (PoP), ball grid arrays
(BGAs), chip scale packages (CSPs), plastic leaded chip carrier
(PLCC), plastic dual in-line package (PDIP), die in waffle pack,
die in wafer form, chip on board (COB), ceramic dual in-line
package (CERDIP), plastic metric quad flat pack (MQFP), thin quad
flat pack (TQFP), small outline IC (SOIC), shrink small outline
package (SSOP), thin small outline package (TSOP), system in
package (SIP), multi-chip package (MCP), wafer-level fabricated
package (WFP), or wafer-level processed stack package (WSP).
[0188] The foregoing is illustrative of the present inventive
concept and is not to be construed as limiting thereof. Although a
few exemplary embodiments have been described, those skilled in the
art will readily appreciate that many modifications to the
described exemplary embodiments are possible without materially
departing from the novel teachings and advantages of the present
inventive concept. Accordingly, all such modifications are intended
to be included within the scope of the present inventive concept.
Therefore, it is to be understood that the foregoing is
illustrative of various exemplary embodiments and is not to be
construed as limited to the specific exemplary embodiments
disclosed, and that modifications to the disclosed exemplary
embodiments, as well as other exemplary embodiments, are intended
to be included within the scope of the appended claims.
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